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Promising Depression Therapy

By Pam Belluck February 11, 2013 4:48 pmFebruary 11, 2013 4:48 pm

A type of brain stimulation caused by a mild electric current that appears to have minimal negative side effects is showing promise as a potential treatment for major depression, according to several studies.

The experimental therapy, known as transcranial direct current stimulation, or tDCS, involves a low-level charge about one-400th of that used in electroshock treatment. Unlike electroshock (also called electroconvulsive therapy or ECT), which is administered for a few seconds to patients under anesthesia, tDCS is given for 20 to 30 minutes continuously while patients are conscious.

While doctors do not see it replacing electroshock, considered the most effective approach for major depression that has been treatment-resistant and requires urgent attention, tDCS does not appear to cause memory loss as electroshock can. Because it is inexpensive and easily administered, scientists say it might become an alternative or additional treatment for people whose depression is not completely helped by medication.

“I think tDCS could be tried before ECT,” said Dr. Andre R. Brunoni, a psychiatrist at the University of São Paulo in Brazil and an author of a study published last week in The Journal of the American Medical Association-Psychiatry. Or, he said, it could be used “for avoiding drug treatment in patients that cannot use drugs.”

Researchers said Dr. Brunoni’s study is the largest to date of about half a dozen studies in recent years. It is the first comparing tDCS with another treatment — in this case, sertraline, or Zoloft. The study, involving 120 patients, found that tDCS appeared to work about as well as a low dose of Zoloft, and that combined with Zoloft, it worked better than the drug or the stimulation alone.

Zoloft and tDCS were equally safe. A few patients became manic, and some developed redness where electrodes were applied.

Researchers said much more study was needed, and that because the Zoloft dose was lower than what many patients use, it could not be concluded that tDCS works better than the drug.

But, Dr. Matthew V. Rudorfer, associate director for treatment research at the National Institute of Mental Health’s division of services and intervention research, said, “this report provides important further evidence for a possible therapeutic role of tDC stimulation in the treatment of depression.”

Another trial just starting at six sites in the United States and Australia is expected to provide further information on tDCS and depression.

Transcranial direct current stimulation was developed decades ago, but only recently have researchers begun testing it seriously for depression, said Dr. Colleen Loo, a psychiatry professor at the University of New South Wales in Sydney, who has led several tDCS studies and is the principal investigator for the new American-Australian trial.

She said the method, in which two electrodes, an anode and a cathode, are placed on the temples, provides “a mild form of brain stimulation that basically modulates the resting level of the nerve cells” in the brain. The current appears to make “the nerve cells communicate more effectively with other nerve cells” without giving the “strong stimulation that actually makes them fire off messages,” she said.

In her research, as with the newly-published Brazilian trial, patients received repeated treatments over several weeks, and there appeared to be cumulative effects. Dr. Loo also found indications that tDCS might have positive cognitive effects, appearing to enhance thinking speed in depressed people.

Dr. Sarah H. Lisanby, chairwoman of the psychiatry and behavioral sciences department at Duke University and an investigator in the American-Australian trial, sees tDCS as a potential treatment for patients who are not suicidal and whose depression has not responded to psychotherapy or antidepressants.

“TDCS as a technology is very safe — noninvasive, portable, cheap to make,” she said. “It runs on a battery, you can carry it around.” Unlike another relatively new noninvasive treatment, transcranial magnetic stimulation (TMS), now federally approved to treat depression in certain cases, tDCS does not have the rare but real risk of seizures, Dr. Lisanby said.

It is even conceivable tDCS could eventually be used at home, she and others said. But for now, doctors caution against using tDCS-type systems available online because patients would not know important information, like where to place electrodes or how much current to use.

Michael Donnelly, a 56-year-old biology teacher in Sydney participated in two trials led by Dr. Loo. He has suffered from depression for 30 years, he said, often taking two or three medications to control it. But in 2009, he plunged into a deep depression and “nothing, nothing was working,” he said.

In the first study, Mr. Donnelly said he received tDCS treatment five days a week for four weeks, followed by weekly and then biweekly treatments for several months. “Probably within a month, I was coming out of the depression,” he said.

Last year, as his mother was dying from cancer, Mr. Donnelly was concerned he might become suicidal, as he had when his father died in 2001. He participated in another study, where he received at least four weeks of tDCS. When his mother died during that period, “I didn’t crash — I was able to function,” he said. “If this was available as a regular treatment I’d probably go once a month for a charge.”

A version of this article appears in print on 02/12/2013, on page D6 of the NewYork edition with the headline: New Therapy for Depression.